To answer your question

Yes, her technique seems to be a bit different and she doesn't get as much speed as others. The traditional thinking (and correct IMO) is you want as much speed as possible while still being able to launch off your jump leg effectively. Once off the ground, it's a physics problem. That's why there are many who use the bicycle technique in the air - it should in theory help one be able to travel farther in the air before coming down.

You'd think if Brittany does so well at the speed she's currently going the focus should be figuring out how to speed her up but still maintain her launch technique. Then again, the approach quite often taken by coaches is to let athletes do what works for them if they are performing at a high level. Don't know if that's what has happened in this case, but I've definitely seen this quite a bit.